Improved steam-boiler



UNITED STATES PATENT OEEICE.

N. S. BEAN, OF MANCHESTER, NEIV HAMPSHIRE, AND J. G. COLLINS, OF

BOSTON, MASSACHUSETTS, ASSIGN ORS TO THE AMOSKEAG MANUFAC- TURING COMPANY.

IMPROVED STEAM-BOILER.

Specification forming part of I etters Patent No. 29,032, dated July 3, 1860.

To @ZZ whom, it may concern: y

Be it known that we, N. S. BEAN, of Manchester, in Hillsborough county, in the State of New Hampshire, and J. G. COLLINS, of Boston, in the county of Suffolk and State ot' Massachusetts, have invented a new and useful improvement in such vertical tubular steam-boilers as pass the products of combustion through tubes into a smoke-box within the boiler and have the combustionchamber, smoke-box, and tubes surrounded by water, the aim of our invention being to produce a boiler peculiarly adapted for use in steam fire-engines, and wherever a light, safe, powerful portable boiler is required; and we do hereby declare that the following, taken in connection with the drawings which accompany and form part of this specification, is a description of ourinvention so full and exact as to enable those skilled in the art to practice it.

Figures l and 2 show, respectively, in half elevation and vertical section and in half plan and horizontal section a boiler embodying our invention.

The waist d is contracted, so as nearly to touch the outermost tubes, l). These and those surrounded by them extend from the crown-sheet c of the furnace to the upper tube-sheet, d, which forms the lower sheet of the smoke-box. This is made up of d, the ring e, and cover f, the cover being bolted to ring o, which is riveted to e, so as to be removable to get at the ends of the tubes for repairs and cleaning. The chimney is shown as united with f and as extending through the steamspace to the top g of the boiler. This top g is secured to the rings h and i (which are riveted to the outer shell of the boiler and to the chimney) by means of bolts. This affords facilities for getting at the interior of the boiler for repairs and cleaning.

The upper portion of our boiler is expanded beyond the waist in orderto give alarge area of water-level, from which the steam can escape, and a large steam-reservoir from which to supply the steam-cylinder. The base of the boiler is also enlarged beyond the diameter of the waist for the purpose of making the crown-sheet c of the furnace large enough to receive the number of tubes necessary to fill the waist, to give a large grate, so as to supply sufficient air to the lire, which can thus be iliade thin and can depend upon natural draft in getting up steam before the engine is started and the blast applied, and so as to receive a supply of fuel sufficient to crowd the tubes with flame, economy of fuel being of entirely secondary importance in steam fire-engine boilers.

In the construction of our boiler substantially as shown and described, it will be observed that the top of the smoke-box, being below the water-level, forms a most effective heating-surface; also that there is no superabundance of water remote from the heatingsurfaces to add to the weight of the boiler and requiring time to be heated. It will also be seen that while the total quantity of Water contained by the boiler is small the quantity at or near the water-level is comparatively large, which essens the sudden and dangerous fluctuations of the Water-level which are common in most boilers where the ratio of heating-surface to the amount of water approximates to that herein shown.

The object of our invention is to produce a boiler that shall unitelightness with strength; that shall have great and quick steam-producing capacity as compared with its bulk and with its weight when iilled with water in readiness for operation; that shall contain, in comparison with its heating-surface, but a small amount of water, with a large proportion of this located near the water-level; that shall have large grate and evaporative areas, large combustion and steam chambers, and a smoke-box submerged so as to render it effective heating-surface.

The nature of ourinvention consists in the relative arrangement and combination of parts, substantially as herein described, by which the above object is accomplished. Ve are aware that vertical fire-tube boilers have been madewith a submerged smoke-box, but without contraction of the waist, also that they have been made with a contracted waist, but with the tubes, or the smoke-box into which they discharge, extending through the upper or steam space of the boiler. To such boilers We make no Claim. They are defective in the important requirements of a perfeet steam fire-engine boiler.

That we ela-im as new, and desire to secure by Letters Patent of the United States, .is-

The withiii-described relative arrangement of parts in a vertical boiler having fire-tubes, the same consisting;` of au enlarged lire-box and dome, contracted Waist, and submerged smoke-box, substantially as set forth.

N. S. BEAN. J. G. C OLLNS. Witnesses to N. S. B.:

J. D. VATsoN, F. T. E. RICHARDSON. lVituesses to J. G. C.:

W. G. RUSSELL, HENRY W. llAYNEs. 

